Follow IfcRelAdheresToElement so IfcSurfaceFeature road markings import #8375

IfcSurfaceFeature (e.g. road markings) adheres to a host element through
IfcRelAdheresToElement, a [1:1] cardinality hierarchical relationship in the
same family as aggregation, containment and nesting since IFC4.3. The spatial
traversal never followed it, so surface features had no resolvable parent or
container: on import they landed in the Unsorted collection instead of the
host's spatial collection, and were dropped entirely in DECOMPOSITION filter
mode.

Add get_adhered_element (feature to host) to the get_parent resolver chain and
walk HasSurfaceFeatures in get_decomposition, plus a get_surface_features helper
mirroring get_parts/get_contained. With get_parent resolving adherence,
get_container now returns the host's spatial container, so tool.Collector places
surface features under the host. Also follow HasSurfaceFeatures in the Bonsai
DECOMPOSITION filter path so they load in that mode.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/bonsai/bonsai/bim/module/project/operator.py

@@ -1294,6 +1294,11 @@ class LoadProjectElements(bpy.types.Operator):
             if element.IsDecomposedBy:
                 for subelement in element.IsDecomposedBy[0].RelatedObjects:
                     decomposed_elements.add(subelement)
+            # IfcSurfaceFeature (e.g. road markings) adhere to a host element
+            # via IfcRelAdheresToElement, a [1:1] hierarchical relationship in
+            # the same family as aggregation, containment and nesting (IFC4.3).
+            for rel in getattr(element, "HasSurfaceFeatures", ()):
+                decomposed_elements.update(rel.RelatedSurfaceFeatures)
         if decomposed_elements:
             self.append_decomposed_elements(decomposed_elements)
         elements.update(decomposed_elements)